M1200 TDrone payload issue

My payload isn’t releasing for some reason on my plan I have it set on to the correct ser no being 9 and the pwm was set at 1200 I successfully opened and closed the drop changing channel 8 from rcin8 to servo trim max and also servo trim min. Once I put the payload in the craft and closed it back by using servo trim min I then changed it back to rcin8 for the mission but when I did the mission it never released. I also left it on servo trim min to see if that would work as well no luck

Moved to ArduCopter, as this is not a Blog post.

Share the specific parameters that did and didn’t work rather than a somewhat incomplete description of the issue.